Conventionally, there is an inkjet recording apparatus which ejects ink from nozzles to record an image on a recording medium conveyed by a conveyance unit. The nozzles are arranged in a head unit over an image recording range in the width direction, which is orthogonal to the conveying direction of the recording medium. In such an inkjet recording apparatus, a color image may be recorded by using multiple head units which each eject ink of different colors from nozzles.
Further, there is an inkjet recording apparatus having a conveyance unit which places a recording medium on the outer circumferential curved surface of a cylindrical conveyance drum and conveys the recording medium by rotating the conveyance drum around the cylindrical shaft. Patent document 1 discloses an inkjet recording apparatus which records an image by using such a conveyance unit and multiple head units. In such an inkjet recording apparatus, the head units are arranged to be inclined, radially from the cylindrical shaft of the conveying drum, so that nozzle surfaces provided with nozzle openings in each of the head units is substantially in parallel with and facing the outer peripheral curved surface of the conveyance drum. In the inkjet recording apparatus according to Patent Document 1, the head units each have fixing portions which are fixed to predetermined attachment members. The fixing portions are at two portions respectively near both ends in the longitudinal direction of the bottom surface having the nozzle surfaces.
With such arrangement, it is possible to reduce variation in the distances from the openings of the respective nozzles on the nozzle surfaces to the outer circumferential curved surface of the conveyance drum, so that the ink ejected from each of the nozzles lands at an appropriate position of the conveyed recording medium.